Experimental design and methodology overview

¶ … Jammin' Spiders Biology Experiment

The goal of this experiment, conducted in 2001 by Jack Feichtner et al. Of Miami University in Ohio, was to study the effect that music has on spiders. The species of spider chosen for the experiment was Theridiiae, and the effect chosen was the orientation of the spider within a given, created environment. Research had previously revealed that spiders are sensitive to vibration for a number of survival reasons. Spiders do not have very good eyesight, so vibrations are used to sense prey caught in the web and the presence of a possible mate on the web. Previous experiments had been performed on the effects that drugs have on the building of spider webs, and based on this research the students hypothesized that there will be a measurable pattern in how the spiders react to the music, and that the spiders will be attracted to softer vibrations and repelled by harsher vibrations.

The original design of the experiment involved studying regular house spiders within their natural environment, but the webs proved to be too small to evaluate without the aid of equipment not available, and there was not an easy way to measure comparative data easily. The revised experiment design explored how spiders inhabit a given space to properly evaluate one statistically is not available to us. In addition, this design was ineffective, as it did not yield statistical data. Thus, the revised experiment explored the way that spiders inhabit a given space because of musical stimulus. This experiment was significant because it related to the way in which human interaction, and noise such as car horns and telephones, affects spiders.

The materials used in this experiment included 20 spiders (the subjects), 20 clear cylindrical containers (the habitats), two compact disc players with speakers, three compact disks (Bach's Ave Maria, Peter Kruder's Tanto Tempo, and Outkast's Bombs Over Baghdad), crickets to feed the subjects, and a measuring mechanism to determine the spiders orientation.

The twenty spiders were organized into four groups of five spiders each, and each group was kept in a different classroom, each inside of an individual container. The climate was moderate and easily monitored to be consistent. The containers were set up in a line above the speakers that would play the music (except the control group which was exposed to no music). The music played 24 hours a day, and once a day the spider's location in the container was noted. Group one was exposed to Bach's "Ave Maria," chosen for the repetition of rhythm and melody with few variations in meter and beat. Group two was exposed to Peter Kruder's "Tanto Tempo," chosen for the higher levels of vibration and variable beats. Group three was exposed to Outkast's "Bombs over Baghdad," chosen for the loud, steady beats and constant vocals.

On Thursdays the spiders were fed one cricket each, and consumption of the food was noted.

Data was gathered daily for a total of 15 days, introducing the music on the seventh day. The information collected was quantitative, not qualitative. The data collection utilized a transparency slip with a grid wrapped around the clear containers that housed the spiders which allowed easy measurement of each spider's latitudinal location. A circle divided into degrees was placed under each container to measure the angle location of the spider.

The collected data results were analyzed by the Stat View computer program, where multiple tests were run and graphs produced that represented the location of each spider within their environment at each reading.

Various trends between the graphs were observed. The trend for all groups, including the control group, regarding the longitudinal (angular) orientation remained consistent, and the spiders did not tend to be drawn to any specific area of the environment. The pattern for the data was erratic, showing a trend as a whole but not on an individual level. Spiders in groups two and three tended to orient themselves vertically above five units. Spiders 14, 16, 17, and 20 represented 40% of this separated group which did not exhibit the same vertical pattern. Sixty percent of the spiders in groups two and three did in fact orient themselves above the five unit line. However, the statistics were reversed for group one. Group one tended to orient themselves closer to the bottom of the environment; sixty percent of the spiders in group one chose to dwell at or under the five unit mark regularly.

The students conducting this experiment drew a number of conclusions from the data collected. The lack of the discernible pattern in the orientation of the spiders regarding their longitudinal position was an unexpected find. The conclusion reached by the students was that because the environments in which the spiders were contained had such a small circumference, the slightest movement would drastically affect their longitudinal location. Additionally, the height of the container was approximately two to three times as high as the circumference of the container, which is a significant juxtaposition. Therefore, because of the small area of the container, the movements of the spiders appear to be drastic ones, even though they may have only moved a very small amount.

The trend that seemed consistent between groups two and three even though different musical selections were played for those groups can be explained because of the similarities in the music played for the groups. Both the Kruder and Outkast selections had very strong, harsh beats, therefore both vibrating the subjects a lot. The speakers were placed under the spiders, so it did seem likely that the spiders would stay higher in the containers to avoid the foreign vibrations, which they did in these groups. The students concluded that the spiders may have felt confused or threatened by the vibrations that came from the speakers and therefore wanted to get further away from the source. The spiders in group one, which were exposed to the Bach selection, did not have the same desire to escape from the source of the vibrations. The students concluded this is because the vibrations emanated by "Ave Maria" are less invasive, and even speculated that the vibrations were gentle enough from this piece that it may have felt more natural and perhaps even soothing to the spiders.

The students noted that there seemed to be a correlation between music that is found to be "soothing" to human ears and the music that appeared to be less threatening to the spiders.

The students additionally compared this study to those conducted by NASA regarding the effects of chemical influences on spider web building. The students found that it was more difficult to draw conclusions from results that are obtained through environmental manipulation rather than physical exploitation for a number of reasons, but that to a far lesser degree than the chemical manipulation of the NASA experiments, the environmental manipulation of these spiders did affect their pattern of orientation. These results are evidence that humanity can affect the natural world, according to their findings.